Connection devices are commonly used in many scientific fields, including gas chromatography. These uses are well known in the art, and include passing fluid from one conduit to another. To properly perform their functions, connection devices must provide effective seals to ensure accurate testing results.
The gas chromatography field often involves performing tests using extreme temperatures, both high and low. These temperatures can affect connection devices, and thereby alter test results. For example, extreme temperatures have been known to deform connection device parts by expansion or contraction. Extreme temperatures can also cause reorientation or cracking of the connection device components. In these cases and others, the connection device's seals can be affected, permitting gas or other fluid to leak. Also the ferrule will typically undergo a permanent deformation known as compression set. The ferrule is not cracked or broken, but without a temperature compensating load, a small gap can form between the ferrule and it's mating surface, causing leakage.
In addition, thermocycling—alternating between extreme hot temperatures, extreme cold temperatures, and temperate temperatures—can cause cracking, deformation, or reorientation of connection device components, including loosening of threaded parts, etc. One of skill in the art will appreciate the effects of thermocycling on connection devices and the potential for breaking the device's seals and permitting gas or fluid leak.
Moreover, a particular test may require the column, whether packed or capillary, to be set to a particular depth within the instrument cavity. Furthermore, the column's depth may need to be adjusted accurately, or a column may need to be removed and replaced.
Thus, there remains a need in the art for a column connection device employing a method for easily and accurately adjusting the column depth during installation. It would be additionally beneficial to employ a method permitting adjustments to the depth once the connection device is secured to an external device. It is further desirable to provide a single unit connection device with as few removable components as practicable. These needs are in addition to remaining concerns regarding reliable sealing of the connection device around the column and in relation to an external device.